1. Field of the Invention
The invention relates to a handrail for escalators or moving walkways with a grip piece of a thermoplastic elastomer with soft and hard segments, a handrail for escalators or moving walkways with a grip piece of a polymer material and a sliding layer made of a woven fabric with warp threads and weft threads and arranged thereon or connected thereto, extending at least in part over a lower surface—relative to the mounting orientation, and a method for producing handrails of this type.
2. Description of Background and Other Information
Handrails for escalators, moving walkways, or similar applications are used as safety elements for passenger transport. For this purpose, the handrail must render possible a safe grip for the passenger and must withstand the dynamic loads or the environmental influences during operation without being damaged thereby. Handrails known from the prior art have a C-shaped cross section and are usually constructed from a plurality of different materials in order to meet these requirements. The handrail surface that can be touched by the passenger usually comprises an elastomer mixture. Furthermore, the handrail cover protects all of the components lying underneath from diverse environmental influences and must therefore be resistant thereto. To increase the dimensional stability of the handrail cross section, reinforcement inserts, e.g., fabric cords, are used. A sufficiently high lip rigidity, i.e., rigidity of the side areas of the handrail can also be achieved thereby.
The handrail is expected to retain its cross-sectional shape during its entire service life, i.e., the cross section must not be excessively enlarged or excessively reduced during its service life. In addition to a development of great noise, upon contact with the handrail track, the reduction would also lead to heat generation, to drive problems and ultimately to the destruction of the handrail. In turn, the result of an enlargement would be that, on the one hand, the passenger could become jammed between the handrail lip and the guide track and, on the other hand, the handrail could jump out of the guide track.
Furthermore, to absorb longitudinal forces the handrail contains in its cross section so-called tensile carriers that must have a defined minimum breaking strength including in the impact area.
Finally, the so-called sliding layer forms the contact surface of the handrail to the handrail guide or to the handrail drive system.
Currently, essentially three materials are used in the handrail sector for moving walkways or escalators. On the one hand, this is a natural rubber or synthetic styrene butadiene rubber (SBR). Furthermore, there are handrails of Hypalon®, a chlorosulfonated polyethylene, and handrails of polyurethane on the market.
In addition, handrails have also already been described, which comprise at least in part a thermoplastic elastomer.
DE 197 42 258 A1 thus discloses a handrail for escalators and moving walkways with a grip piece of a polymer material, a reinforcing layer absorbing tensile forces, a layer for shape stabilization of textile layers arranged in the transverse direction and a finishing sliding layer. The layers are combined to form a textile structure in one piece and can be connected to the grip piece in a manufacturing operation. The grip piece itself can be made of a thermoplastic elastomer.
DE 198 32 158 A1 describes a handrail for an escalator or a moving walkway with a thermoplastic elastomer that preferably has at least a Shore hardness of 80 and preferably has a C-shaped profile. The inwardly facing surface of the handrail can comprise a section of a different material that preferably has a lower hardness than the rest of the handrail and that moreover is extruded. Ribs or grooves may be provided on the inwardly facing or drive surface of the handrail in order to vary the surface area of contact with the drive means. The use of the hard thermoplastic material to form the nose and the outer section of the handrail increases shape retention during extensive use and lowers the requirement for further reinforcement. The friction between the guide means on which the handrail travels is also reduced.
DE 299 03 376 U1 discloses a handrail for escalators and moving walkways that is produced (extruded) from a thermoplastic elastomer (TPE, TPO, TPU), preferably a thermoplastic polyurethane elastomer. A tensile carrier that is located in the center of the handrail is embodied as a roller chain with lateral bolts and can be clipped from below in a positive manner into a recess provided for this purpose. Hollow channels can be provided in the extruded profile, which channels help to save material as well as reducing the bending stiffness. Channels located to the right and to the left next to the tensile carrier recess can be provided on the underside of the handrail, in which channels the balustrade guide of the escalator runs. A thin-walled hose of ultra high molecular weight polyethylene (alternatively polytetrafluoroethylene) can be arranged therein, which hose is compressed when fixed onto the balustrade guide. The friction coefficient between guide and handrail and the abrasive wear are thereby reduced to a minimum.
Finally, handrails are also described, which comprise at least in part a thermoplastic material. For example, a handrail with a C-shaped profile is known from WO 00/01607 A, which handrail comprises a first layer of a thermoplastic material, a second layer of a likewise thermoplastic material, which second layer is arranged on the first layer and defines the outer surface of the hand rail, as well as a sliding layer that is arranged on the lower first thermoplastic layer. A tensile carrier is incorporated into the first layer and this first layer is of a harder thermoplastic material than the second layer.